发明名称 |
Capacitive distance sensor |
摘要 |
A distance sensor has a capacitive element in turn having a first capacitor plate which is positioned facing a second capacitor plate whose distance is to be measured. In the case of fingerprinting, the second capacitor plate is defined directly by the skin surface of the finger being printed. The sensor comprises an inverting amplifier, between the input and output of which the capacitive element is connected to form a negative feedback branch. By supplying an electric charge step to the input of the inverting amplifier, a voltage step directly proportional to the distance being measured is obtained at the output.
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申请公布号 |
US6114862(A) |
申请公布日期 |
2000.09.05 |
申请号 |
US19980040261 |
申请日期 |
1998.03.09 |
申请人 |
STMICROELECTRONICS, INC. |
发明人 |
TARTAGNI, MARCO;GUPTA, BHUSAN;KRAMER, ALAN |
分类号 |
G01B7/00;A61B5/117;G01B7/004;G01B7/02;G01B7/287;G01B7/34;G06K9/00;(IPC1-7):G01R27/26 |
主分类号 |
G01B7/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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